Combustion and Flame, Vol.210, 43-53, 2019
A mixture of hydrogen peroxide and tetraglyme as a green energetic monopropellant
An effort is presented to seek a promising candidate for a green energetic monopropellant based on hydrogen peroxide. The novel premixed monopropellant is composed of 90 wt.% H2O2 as the oxidizer and tetraglyme (C10H22O5) as the fuel. Different mixture ratios were prepared by varying the weight percentage of the fuel in the mixture, and the mixtures were named HPM-08 (8 wt.% of fuel), HPM-12 (12 wt.% of fuel), and HPM-20 (20 wt.% of fuel). The theoretical performance of the mixtures was estimated, and their thermostability in air was evaluated via thermogravimetric analysis. A small-scale packed-bed catalytic reactor was utilized to assess the feasibility of the catalytic ignition of HPM-08 with a lanthanum-doped manganese oxide catalyst. Ground hot-firing tests were implemented with an engineering model monopropellant thruster on the scale of 10 N. The demonstrations of the thruster operation using HPM-08 and HPM-12 were successful, but an explosion was caused in the case of HPM-20. A technical speculation suggested that the explosion could be closely related to the phenomenon of detonation. In this study, the configuration of the catalyst bed was regarded as the principal factor in the triggering of detonation in the thruster module. The packed-bed-type catalyst bed containing millimeter-scale pellets may accelerate the phenomenon of deflagration-to-detonation transition, resulting from the rapid compressive heating process based on the superposition of the pressure waves. These results should be taken into account during the design of the catalyst bed in order to utilize particular types of this premixed monopropellant. In addition, a new ignition technique may be applied to prevent the explosion. (C) 2019 The Combustion Institute. Published by Elsevier Inc. All rights reserved.